Re: [Qemu-devel] [PATCH 2/2] ipmi: Use proper struct reference for BT vmstate

[Dr. David Alan Gilbert]

* miny...@acm.org (miny...@acm.org) wrote:
> From: Corey Minyard 
> 
> The vmstate for isa_ipmi_bt was referencing into the bt structure,
> instead create a bt structure separate and use that.
> 
> The version 1 of the BT transfer was fairly broken, if a migration
> occured during an IPMI operation, it is likely the migration would
> be corrupted because I misunderstood the VMSTATE_VBUFFER_UINT32()
> handling, I thought it handled transferring the length field,
> too.  So I just remove support for that.  I doubt anyone is using
> it at this point.
> 
> This also removes the transfer of use_irq, since that should come
> from configuration.
> 
> Signed-off-by: Corey Minyard 
> ---
>  hw/ipmi/isa_ipmi_bt.c | 43 ++-
>  1 file changed, 30 insertions(+), 13 deletions(-)
> 
> diff --git a/hw/ipmi/isa_ipmi_bt.c b/hw/ipmi/isa_ipmi_bt.c
> index e946030..a990ab7 100644
> --- a/hw/ipmi/isa_ipmi_bt.c
> +++ b/hw/ipmi/isa_ipmi_bt.c
> @@ -450,22 +450,39 @@ static void isa_ipmi_bt_realize(DeviceState *dev, Error 
> **errp)
>  isa_register_ioport(isadev, >bt.io, iib->bt.io_base);
>  }
>  
> -static const VMStateDescription vmstate_ISAIPMIBTDevice = {
> -.name = TYPE_IPMI_INTERFACE,
> +
> +const VMStateDescription vmstate_IPMIBT = {
> +.name = TYPE_IPMI_INTERFACE_PREFIX "bt",
>  .version_id = 1,
>  .minimum_version_id = 1,
>  .fields  = (VMStateField[]) {
> -VMSTATE_BOOL(bt.obf_irq_set, ISAIPMIBTDevice),
> -VMSTATE_BOOL(bt.atn_irq_set, ISAIPMIBTDevice),
> -VMSTATE_BOOL(bt.use_irq, ISAIPMIBTDevice),
> -VMSTATE_BOOL(bt.irqs_enabled, ISAIPMIBTDevice),
> -VMSTATE_UINT32(bt.outpos, ISAIPMIBTDevice),
> -VMSTATE_VBUFFER_UINT32(bt.outmsg, ISAIPMIBTDevice, 1, NULL, 
> bt.outlen),
> -VMSTATE_VBUFFER_UINT32(bt.inmsg, ISAIPMIBTDevice, 1, NULL, bt.inlen),
> -VMSTATE_UINT8(bt.control_reg, ISAIPMIBTDevice),
> -VMSTATE_UINT8(bt.mask_reg, ISAIPMIBTDevice),
> -VMSTATE_UINT8(bt.waiting_rsp, ISAIPMIBTDevice),
> -VMSTATE_UINT8(bt.waiting_seq, ISAIPMIBTDevice),
> +VMSTATE_BOOL(obf_irq_set, IPMIBT),
> +VMSTATE_BOOL(atn_irq_set, IPMIBT),
> +VMSTATE_BOOL(irqs_enabled, IPMIBT),
> +VMSTATE_UINT32(outpos, IPMIBT),
> +VMSTATE_UINT32(outlen, IPMIBT),
> +VMSTATE_UINT8_ARRAY(outmsg, IPMIBT, MAX_IPMI_MSG_SIZE),
> +VMSTATE_UINT32(inlen, IPMIBT),
> +VMSTATE_UINT8_ARRAY(inmsg, IPMIBT, MAX_IPMI_MSG_SIZE),
> +VMSTATE_UINT8(control_reg, IPMIBT),
> +VMSTATE_UINT8(mask_reg, IPMIBT),
> +VMSTATE_UINT8(waiting_rsp, IPMIBT),
> +VMSTATE_UINT8(waiting_seq, IPMIBT),

OK, without knowing anything about the internals of the IPMI model, this
looks simpler; and yes, vbuffer isn't very smart.

You should probably consider either a postload to verify the data,
or be a bit paranoid in the uses.  For example, imagine that 'outpos'
and 'outlen' were for some reason completely bogus huge values and then
you got to ipmi_bt_ioport_read case 1, I think you could read off the
end of outmsg.

Dave

> +VMSTATE_END_OF_LIST()
> +}
> +};
> +
> +static const VMStateDescription vmstate_ISAIPMIBTDevice = {
> +.name = TYPE_IPMI_INTERFACE_PREFIX "isa-bt",
> +.version_id = 2,
> +.minimum_version_id = 2,
> +/*
> + * Version 1 had messed up the array transfer, it's not even usable
> + * because it used VMSTATE_VBUFFER_UINT32, but it did not transfer
> + * the buffer length, so random things would happen.
> + */
> +.fields  = (VMStateField[]) {
> +VMSTATE_STRUCT(bt, ISAIPMIBTDevice, 1, vmstate_IPMIBT, IPMIBT),
>  VMSTATE_END_OF_LIST()
>  }
>  };
> -- 
> 2.7.4
> 
> 
--
Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK

[Qemu-devel] [PATCH 2/2] ipmi: Use proper struct reference for BT vmstate

[minyard]

From: Corey Minyard 

The vmstate for isa_ipmi_bt was referencing into the bt structure,
instead create a bt structure separate and use that.

The version 1 of the BT transfer was fairly broken, if a migration
occured during an IPMI operation, it is likely the migration would
be corrupted because I misunderstood the VMSTATE_VBUFFER_UINT32()
handling, I thought it handled transferring the length field,
too.  So I just remove support for that.  I doubt anyone is using
it at this point.

This also removes the transfer of use_irq, since that should come
from configuration.

Signed-off-by: Corey Minyard 
---
 hw/ipmi/isa_ipmi_bt.c | 43 ++-
 1 file changed, 30 insertions(+), 13 deletions(-)

diff --git a/hw/ipmi/isa_ipmi_bt.c b/hw/ipmi/isa_ipmi_bt.c
index e946030..a990ab7 100644
--- a/hw/ipmi/isa_ipmi_bt.c
+++ b/hw/ipmi/isa_ipmi_bt.c
@@ -450,22 +450,39 @@ static void isa_ipmi_bt_realize(DeviceState *dev, Error 
**errp)
 isa_register_ioport(isadev, >bt.io, iib->bt.io_base);
 }
 
-static const VMStateDescription vmstate_ISAIPMIBTDevice = {
-.name = TYPE_IPMI_INTERFACE,
+
+const VMStateDescription vmstate_IPMIBT = {
+.name = TYPE_IPMI_INTERFACE_PREFIX "bt",
 .version_id = 1,
 .minimum_version_id = 1,
 .fields  = (VMStateField[]) {
-VMSTATE_BOOL(bt.obf_irq_set, ISAIPMIBTDevice),
-VMSTATE_BOOL(bt.atn_irq_set, ISAIPMIBTDevice),
-VMSTATE_BOOL(bt.use_irq, ISAIPMIBTDevice),
-VMSTATE_BOOL(bt.irqs_enabled, ISAIPMIBTDevice),
-VMSTATE_UINT32(bt.outpos, ISAIPMIBTDevice),
-VMSTATE_VBUFFER_UINT32(bt.outmsg, ISAIPMIBTDevice, 1, NULL, bt.outlen),
-VMSTATE_VBUFFER_UINT32(bt.inmsg, ISAIPMIBTDevice, 1, NULL, bt.inlen),
-VMSTATE_UINT8(bt.control_reg, ISAIPMIBTDevice),
-VMSTATE_UINT8(bt.mask_reg, ISAIPMIBTDevice),
-VMSTATE_UINT8(bt.waiting_rsp, ISAIPMIBTDevice),
-VMSTATE_UINT8(bt.waiting_seq, ISAIPMIBTDevice),
+VMSTATE_BOOL(obf_irq_set, IPMIBT),
+VMSTATE_BOOL(atn_irq_set, IPMIBT),
+VMSTATE_BOOL(irqs_enabled, IPMIBT),
+VMSTATE_UINT32(outpos, IPMIBT),
+VMSTATE_UINT32(outlen, IPMIBT),
+VMSTATE_UINT8_ARRAY(outmsg, IPMIBT, MAX_IPMI_MSG_SIZE),
+VMSTATE_UINT32(inlen, IPMIBT),
+VMSTATE_UINT8_ARRAY(inmsg, IPMIBT, MAX_IPMI_MSG_SIZE),
+VMSTATE_UINT8(control_reg, IPMIBT),
+VMSTATE_UINT8(mask_reg, IPMIBT),
+VMSTATE_UINT8(waiting_rsp, IPMIBT),
+VMSTATE_UINT8(waiting_seq, IPMIBT),
+VMSTATE_END_OF_LIST()
+}
+};
+
+static const VMStateDescription vmstate_ISAIPMIBTDevice = {
+.name = TYPE_IPMI_INTERFACE_PREFIX "isa-bt",
+.version_id = 2,
+.minimum_version_id = 2,
+/*
+ * Version 1 had messed up the array transfer, it's not even usable
+ * because it used VMSTATE_VBUFFER_UINT32, but it did not transfer
+ * the buffer length, so random things would happen.
+ */
+.fields  = (VMStateField[]) {
+VMSTATE_STRUCT(bt, ISAIPMIBTDevice, 1, vmstate_IPMIBT, IPMIBT),
 VMSTATE_END_OF_LIST()
 }
 };
-- 
2.7.4